It's certainly different from S1 in that the vast majority of sketches were of walkers. It may seem like there are too many Ricks for S2, but I for one am happy for a better chance at getting a nice character sketch lol.

Robert Hendrickson, who did all Rick and Lori sketches for example, I get the feeling he was told by Crypto that that is all he is allowed to draw (I know for a fact that each artist is explicitly told who they can and can't draw).